/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package argentracker.activeentity.metadata;

import java.lang.reflect.Modifier;

import com.google.appengine.api.datastore.Entity;

import argentracker.activeentity.ActiveEntity;

/**
 * briefly description.
 * 
 * extense description.
 * 
 * @author matero (matero _at_ gmail _dot_ com)
 */
public abstract class ActiveEntityMetadata<AE extends ActiveEntity<AE>> {

    public static <AE extends ActiveEntity<AE>> ActiveEntityMetadata<AE> forClass(Class<AE> aeClass) {
        return isAbstract(aeClass) ? new AbstractActiveEntityMetadata<AE>(aeClass)
                : new ConcreteActiveEntityMetadata<AE>(aeClass);
    }

    private static boolean isAbstract(Class<?> activeEntityClass) {
        return Modifier.isAbstract(activeEntityClass.getModifiers());
    }

    public final Class<AE> aeClass;
    public final String kind;

    /**
     * Constructs the metadata for an Active Entity class.
     */
    protected ActiveEntityMetadata(Class<AE> activeEntityClass) {
        this.aeClass = activeEntityClass;
        this.kind = activeEntityClass.getSimpleName();
    }

    public abstract boolean isAbstract();
    
    public abstract AE newActiveEntity();
    
    public AE createActiveEntityFor(Entity e) {
        return newActiveEntity().load(e);
    }
}
